silvestri



No. 616,592. Patented Dec. 27, I898.

G. SILVESTRI.

ROTARY MOTOR.

(Application filed. Dec. 30, 1897.) (No Model.) 2 Shuts-Sheet l.

TM: mums PETERS co vuorwuwa. WASNXNGTON, n 1

Patanted Dec. 27, I898. G. SILVESTRI.

ROTARY MUTGH.

(Application filfid Dec 30, 1897.)

2 Sheets-Sheet 2.

No. 6i6,592

Modal.)

UNHE STATES GIULIO SILVESTRI, OF VIENNA, AUSTRIA-HUNGARY. Y

ROTARY M 0T0 R;

- SPECIFICATION forming part of Letters Patent No. 616,592, datedDecember a, 1898.

Application filed December 30, 1897. Serial No. 664,631. (No model.)

.To (0 whom it may concern:

Be it known that I, GIULIO Srnvnsrnr, engineer, a subject of the Emperorof Austria- Ilungary, residing in the city of Vienna, in the Province ofLower Austria, in the Empire of Austria-Hungary, have invented certainnew and useful Improvements, in Rotary Motors, of which the following isa specification.

All the rotary motors with cylindrical pistons heretofore employedpossess the deficiency of being difficult to tighten. Besides, they workwith-too great a friction. These two factors and the relief of thepiston, however, are the main conditions for a practical rotary motor.

My invention relates to the construction of a rotary motor which differsfrom others of this kind in possessing a conical piston instead. of acylindrical one, and its steam-chad nels are in constant connection withthe steam-admitting device. This connection is in my improved motor notbroken by a subsequent taking up for wear of the piston. Thesteam-channels are so proportioned and arranged on the piston that thelatter one is perfectly relieved both in respect to the pressure exertedupon the projection surfaces of -the channels as well as regarding theexisting turning moments. Further, the conical form of the piston andcylinder enables an exact tightening up of the piston in accordance withits wear.

The invention is illustrated in the accompanying drawings, in which-Figure 1 illustrates my rotary motor in horizontal section. Fig. 2 is avertical section of the same. Figs. 3 and 4 are two side views of themotor on a reduced scale.

The main part of the motor is the rotating piston b, of conical form,which rotates steamtight in a conical case a. The conical piston has forits object to fit tightly from the beginning and to make it possible totighten up the piston according to wear.

The piston b is provided on its mantlesurface with three annularchannels B Z) Z), of trapezoidal section, which channels are so arrangedregarding size and location that they effect a perfect relief of thepiston. This is done in the following manner: The sum of the projectedsurfaces of the two lateral channels b b (which must not, however, havethe pieces D (Z d.

same area) must be equal to the projected lateral channels must fall inline with the resultant of the pressures on the middle channel, but musthave the opposite direction, so that no turning moments occur. In thiscase a perfect relief of the piston is obtained because steam isadmitted into the middle or central channel B exactly on the oppositeside of the two lateral channels I) 1). channels are in the rotatingbody, they are closed by the piston itself on three sides, so that onlythe fourth side is to be tightened. This can be effected in a simple butperfect form by virtue of the conical shape of the piston-body.

Each of the annular channels is broken on two diametrically oppositepoints by sliding The sliding pieces are larger than the channels andare guided in radial slots on the piston or piston-arms. They arepressed outward steam-tight against the inner wall of the casing bysprings D" d (1. As above mentioned, the sliding pieces D d d are widerthan the channels. This has for its obj ect to effect asurface-tightening of the guiding-slots. In the channels 13 b b engagesomewhat smaller segments G c c, which are held tight on the inner wallof the casing a and serve to separate the steam-inlet side and theexhaust or discharge side of the channels which are on the right andleft side of the sliding pieces D (Z (Z. It further serves to effect themotion of the sliding pieces D cl d, and thereby the alternating inletinto and discharge from the spaces in the annular channels 13 b b, whichare inclosed by the two sliding pieces. The segments 0 c c are soarranged that thelarge segment 0, engaging the central channel 13, isexactly opposite to the two segments 0 c, which engage the two smalllateral channels I) b for the purpose of admitting the steam fromopposite sides with the same force on the piston and the sliding pieces,so that the piston is perfectly relieved. Each of the segments 0 c 0possesses two channels 0 c c and C 0 0 which are in front of or beforethe steam-conducting channels of the cylinder a and serve for theadmission and discharge of steam into the piston-channels B b b.

As the The channels for the central section are designated by H H andthe channels for the smaller segments are designated by h h They have onthe embouching-points H H 7L1 h W 71- an enlarged cross-section on theinner wall of the casing in order to maintain the full cross-section ofthe channels C c c and O c c of the segments, so that the admission ofsteam is not diminished while the piston b is tightened up. In theillustrated form the channels H H and 72.1 71. are cast into thecylinder-body a; but it is obvious that these channels may also beconstructed of piping. The location of this channel for the largesegment is shown in Fig. 4, and the location of the channels for the twosmall segments is shown in Fig. 3.

It is readily understood that the channels H h It may effect theadmission of steam as well as the channels H h2 71 and accordingly theengine will run backward or forward. The cylinder a is closed on bothsides by hollow covers g g, having openings g g g g which fit the endopenings of the channels in the flanges, so that one hollow coverreceives the fresh steam and the other the exhauststeam from thecylinder. Each hollow cover is connected to a pipe-conduit at points gg", I

one conduit serving for the admission of steam, the other for theexhaust of the same.

In order to obtain a perfect tightening between the segments 0 c c andthe sliding pieces D d d and the channels B b I), each of the segmentsis provided with an automatic adjustingandtightening device. Thesegmentsare grooved in the center in such a manner that they form yokes orbridges C c c The yokes are embraced by tightening-straps N n 'n, offlexible metal sheeting, preferably of copper. The edges of these strapsare turned over and extend below the yokes, the extensions beingsomewhat inclined or oblique. Here are provided engaging wedges or keysN N n n n n, which are distanced by a spring f as long as the wedgesbear against the oblique edges of the channels. The closure is nottight, and the straps N n 'n are worn only on their broad surface.According to such wear the wedges which are separated by the spring fare hereby pressed forward until they bear tightly against the obliquesurfaces of the channels,thus effecting a perfect closure. Further wearof the wedges and straps takes place, and in accordance with such wearthe wedges are automatically pressed forward by the springs f, therebyassuring a constant and perfect tightening. Care should be taken toselect proper force for pressing in the wedges. By proper adjustment orsetting of the keys or wedges involuntary removal is prevented, even athigh steam-pressure, so that the tightening device is reliablyself-acting.

The working of the motor may be understood from the drawings. The steamentering, for instance, through hollow cover g will be distributed bythe channels D d d and passes through openings H h h and then throughthe segment-channels C c c, behind each of the sliding pieces located infront of the segment-channels, and pushes the sliding pieces forward,together with piston I), thus effecting a rotation of the piston of onehundred and eighty degrees. In this moment a second sliding piecearrives in front of the opening, admitting the steam, effecting a further rotation of the piston, because the steam acts now on the secondsliding piece, and so on. At each revolution each sliding piece passesclose on the segment, and when leaving it it receives live steam. Thereturn of the sliding pieces into their slots is effected by the segmentitself. The renewed forward motion, however, chiefly is effected by thesprings behind the sliding pieces and by centrifugal force and partly bythe steam-pressure, too. Each sliding piece is provided with a bore oropening D 01 61 through which the steam may discharge when movedbackward by the segment. Thereby the rearward motion of the slidingpieces is essentially facilitated. After passing the segment-closingdevice steam passes through the openings D d 01 behind the slidingpieces, and assists the spring force acting in the outward direction.

In order to effect a uniform reciprocating motion of the sliding pieces,it is preferable to shape the surfaces of the segments para= boliform.The active surface is composed of four equal surfaces of paraboliformshape, of which the two outside surfaces have the concave side towardthe piston, while the two inner adjoining surfaceshave the convex sidetoward the same. In order to have both ends of the parabolasubstantially strong, it is advisable to sink the pieces of the segmentsa little into the cylinder.

If it is desired to rotate the motor in opposite direction, then theadmission of steam is reversed, so that steam enters into the hol lowcover g, while the exhaust-steam passes through the hollow cover g. Thisreversion of the steam may be effected by any known device, preferablyby valves.

The motor may also be provided with a device for varying the degree ofexpansion; but this is not essential for the purpose of this invention.I wish to further point out that the number of channels B b b must notbe exactly three, but that any other number may be employed; but caremust be taken. that the resultants of the pressures be always equal andof opposite direction, so that no turning moment exists, insuring anequal pressure on the journals and therebya perfect uniform motion ofthe motor.

It is obvious that the machine employed as a driving apparatus may beused as a pump. It is further obvious that it may be used as awater-meter, turbine, air-motor, or explosion-motor, &c.

I do not limit myself to exact dimensions and materials or to anyconstruction of dc tails.

Having thus described my invention, what I claim therein as new, anddesire to secure by Letters Patent, is-

1. A rotary motor consisting of a conical piston rotating steam-tight ina conical case a and provided with recessed annular channels B, b, b oftrapezoidal section, movable sliding pieces D, (Z, (Z breaking thechannels on two diametrically opposite points, radial slots guiding thesliding pieces, segments 0,

c, c, engaging the channels and possessing combination of segments C, c,a serving for the motion of sliding pieces D, d, cl closing thesteam-channels, a self-adjusting tightening device between the segmentsand the somewhat larger piston-channels B, b, b, yokes C 0 0 provided inthe segments straps N, n, n of flexible metal embracing the yokes andcorresponding exactly to the crosssection of the piston-channels andwedges N, 01, 7t engaging the straps below the channels, springs factuating the wedges and engaging under the outwardly-bent edges of thestraps whereby the edges are automatically adjusted for the purpose ofeffecting a perfect ti ghtening, substantially as described.

In testimony whereof I have signed this specification in presence of twosubscribing witnesses.

GIULIO SILVESTRL "Witnesses:

HENRY O. CARPENTER, CHAS. E. CARPENTER.

